The present invention relates to gear cutting machines and the like and in particular, to a compact, high through-put gear machine.
The cutting of gears may be performed on a gear machine in which a gear blank (workpiece) is rotated synchronously with a cutting tool (hub). The ratio of the rotational rates of the blank and cutter and the relative angle of rotation of the blank and cutter determine the gear tooth structure and must be accurately controlled.
Traditionally, the blank and cutter are driven by a conventional mechanical power train having a selectable gear drive for changing the relative rotation rate between these elements. The need for a precise gear drive with no play and the high demands for precision in gear cutting limit the through-put of such gear cutting machines. Through-put is a measure of how fast a gear can be cut.
With the advent of carbide hobs and high quality DC servo-drive systems, there has been some development efforts directed to high through-put gear machines in which rotation of the blank and cutter (and control of their relative rates of rotation) is performed electronically through a so-called electronic gear box driving independent DC servo motors. With elimination of the mechanical power train and the use of a carbide tool, the absolute speed of rotation of the blank and cutter may be increased significantly. Unfortunately, the cost of the large horsepower servo motors and the additional demands on machine rigidity caused by the faster cutting speeds, has made these initial machines extremely expensive. Further, the accuracy of these machines has not been fully acceptable.